Local oscillator using non-radiative dielectric waveguide

Abstract

Disclosed is a local oscillator utilizing an NRD guide applicable to a millimeter wave integrated circuits. A Gunn diode is buried in a bottom of a housing so that a heat generated from the Gunn diode is directly transferred to the housing and is rapidly emitted. Thus, an oscillating power and an oscillating frequency obtained from the local oscillator can be stabilized due to efficient heat-emission. Since a diode mount is not required, manufacturing costs can be reduced while productivity increases. A metal rod resonator, which is easily assembled and has good power and frequency stability as compared with a microstrip resonator, is used as a resonating device. The metal rod resonator is inserted into a fixing block in perpendicular to the NRD guide. An end of the metal rod resonator directly makes contact with an anode of the gun diode. A cavity forming member for defining a cavity, which surrounds main components including the Gunn diode, is installed in the housing. A local oscillator module can be protected and the oscillating power and the oscillating frequency can be stably maintained under a frequency band satisfying a cavity condition.

What is claimed is:  
     
       1. A local oscillator comprising: 
       a Gunn diode for generating an oscillating signal of millimeter wavelength by using a bias voltage;  
       a resonating member for tuning a power of an oscillating signal and a frequency thereof;  
       an NRD guide for guiding the oscillating signal inputted into an input terminal thereof to an output terminal thereof;  
       an LSE mode suppressor inserted into the input terminal of the NRD guide, for preventing an LSE mode of the oscillating signal transferred from the resonating member from passing therethrough while allowing an LSM mode of the oscillating signal to pass therethrough; and  
       a housing including an upper conductive plate and a lower conductive plate, for accommodating the Gunn diode, the resonating member, the NRD guide, the LSE mode suppressor therewithin;  
       wherein the Gunn diode is vertically buried in a first coupling hole formed at a bottom of the lower conductive plate such that an anode thereof is exposed to an exterior so as to directly transfer a heat generated from the Gunn diode to the lower conductive plate; and  
       wherein the resonating member includes a fixing block which is installed to be in contact with the input terminal of the NRD guide and is formed with a second coupling hole, and a metal rod resonator which is inserted into the fixing block to be arranged in perpendicular to a length direction of the NRD guide, and one end thereof being exposed to make direct contact with an anode of the Gunn diode.  
     
     
       2. The local oscillator as claimed in  claim 1 , wherein the Gunn diode is screw-coupled into the first coupling hole. 
     
     
       3. The local oscillator as claimed in  claim 1 , where the fixing block is press-fitted into a mounting groove formed at the lower conductive plate. 
     
     
       4. The local oscillator as claimed in  claim 1 , wherein an end of the metal rod resonator and the anode of the Gunn diode are directly coupled to each other by soldering. 
     
     
       5. A local oscillator comprising: 
       a Gunn diode for generating an oscillating signal of millimeter wavelength by using a bias voltage;  
       a resonating member for tuning a power of an oscillating signal and a frequency thereof;  
       an NRD guide for guiding the oscillating signal inputted into an input terminal thereof to an output terminal thereof;  
       an LSE mode suppressor inserted into the input terminal of the NRD guide, for preventing an LSE mode of the oscillating signal transferred from the resonating member from passing therethrough while allowing an LSM mode of the oscillating signal to pass therethrough; and  
       a housing including an upper conductive plate and a lower conductive plate, for accommodating the Gunn diode, the resonating member, the NRD guide, the LSE mode suppressor therewithin;  
       wherein the Gunn diode is vertically buried in a first coupling hole formed at a bottom of the lower conductive plate such that an anode thereof is exposed to an exterior so as to directly transfer a heat generated from the Gunn diode to the lower conductive plate;  
       further comprising a bias choke which rejects a harmonic component of a bias power supplied from a bias feeding through so as to transfer a DC bias into the Gunn diode, the bias choke being fabricated by etching a thin copper film in a form of a microstrip and being arranged in parallel on the lower conductive plate, the bias feeding through and the Gunn diode being coupled to each other by a wire.  
     
     
       6. The local oscillator as claimed in  claim 5 , further comprising a cavity forming member which is installed in the housing for stabilizing the power of the oscillating signal and the frequency thereof, the cavity forming member being formed with an opening through which the NRD guide passes and defining a cavity which surrounds the input terminal of the NRD guide, the Gunn diode, the resonating member and the mode suppressor. 
     
     
       7. The local oscillator as claimed in  claim 6 , wherein the cavity forming member is formed at a bottom thereof with a bias choke passing groove, the bias choke being positioned in a space defined by the lower conductive plate and the groove. 
     
     
       8. The local oscillator as claimed in  claim 6 , wherein a λ/4 groove is formed on a bottom of the cavity forming member along a length direction thereof to reduce a leaky wave of the housing. 
     
     
       9. The local oscillator as claimed in  claim 6 , wherein the cavity forming member and the lower conductive plate are assembled with screws for tuning the frequency by screw-coupling the screws into screw holes which are respectively formed at corresponding locations of the cavity forming member and the lower conductive plate. 
     
     
       10. A local oscillator comprising: 
       a Gunn diode for generating an oscillating signal of millimeter wavelength by using a bias voltage;  
       a resonating member for tuning a power of an oscillating signal and a frequency thereof;  
       an NRD guide for guiding the oscillating signal inputted into an input terminal thereof to an output terminal thereof;  
       an LSE mode suppressor inserted into the input terminal of the NRD guide, for preventing an LSE mode of the oscillating signal transferred from the resonating member from passing therethrough while allowing an LSM mode of the oscillating signal to pass therethrough;  
       a housing including an upper conductive plate and a lower conductive plate, for accommodating the Gunn diode, the resonating member, the NRD guide, the LSE mode suppressor therewithin; and  
       a cavity forming member installed in the housing for stabilizing the oscillating signal, the cavity forming member being formed with an opening through which the NRD guide passes and defining a cavity which surrounds the input terminal of the NRD guide, the Gunn diode, the resonating member and the mode suppressor;  
       wherein the cavity forming member and the lower conductive plate are assembled with screws for tuning the frequency by screw-coupling the screws into screw holes which are respectively formed at corresponding locations of the cavity forming member and the lower conductive plate.  
     
     
       11. The local oscillator as claimed in  claim 10 , wherein a λ/4 groove is formed on a bottom of the cavity forming member along a length direction thereof to reduce a leaky wave of the housing. 
     
     
       12. The local oscillator as claimed in  claim 10 , wherein the cavity forming member is formed at a bottom thereof with a passing groove for a bias choke which is positioned in a space defined by the lower conductive plate and the passing groove and rejects a harmonic component of a bias current to provide a DC bias to the Gunn diode as the bias voltage for driving the Gunn diode. 
     
     
       13. A local oscillator comprising: 
       a Gunn diode for generating an oscillating signal of millimeter wavelength by using a bias voltage;  
       a resonating member for tuning a power of an oscillating signal and a frequency thereof;  
       an NRD guide for guiding the oscillating signal inputted into an input terminal thereof to an output terminal thereof;  
       an LSE mode suppressor inserted into the input terminal of the NRD guide, for preventing an LSE mode of the oscillating signal transferred from the resonating member from passing therethrough while allowing an LSM mode of the oscillating signal to pass therethrough;  
       a cavity forming member formed with an opening through which the NRD guide passes for defining a cavity which surrounds the input terminal of the NRD guide, the Gunn diode, the resonating member and the mode suppressor; and  
       a housing including an upper conductive plate and a lower conductive plate, for accommodating the Gunn diode, the resonating member, the NRD guide, the LSE mode suppressor and the cavity forming member therewithin,  
       wherein the resonating member includes a fixing block which is installed to be in contact with the input terminal of the NRD guide an is formed with a second coupling hole, and a metal rod resonator which is inserted into the fixing block to be arranged in perpendicular to a length direction of the NRD guide, one end thereof being exposed to make direct contact with an anode of the Gunn diode; and  
       the cavity forming member and the lower conductive plate are assembled with screws for tuning the frequency by screw-coupling the screws into screw holes which are respectively formed at corresponding locations of the cavity forming member and the lower conductive plate.  
     
     
       14. The local oscillator as claimed in  claim 13 , wherein a λ/4 groove is formed on a bottom of the cavity forming member along a length direction thereof to reduce a leaky wave of the housing. 
     
     
       15. The local oscillator as claimed in  claim 13 , wherein the fixing block is press-fitted into a mounting groove formed at the lower conductive plate. 
     
     
       16. The local oscillator as claimed in  claim 13 , wherein the Gunn diode is vertically buried in a first coupling hole formed at a bottom of the lower conductive plate such that an anode thereof is exposed to an exterior so as to directly transfer a heat generated from the Gunn diode to the lower conductive plate.